Starting device for synchronous motors



Nov. 25. 1930. w. s. PFElr-ER 1,782,908

STARTING DEVICE Foa sYNcHRoNoUs morons iilgd Im;-4 lf. 1925 2 Sheets-Sheet 1 Waker E Pf Elf' ELA W Nov. 25, 1930. w. s( PFEIFER STARTING DEVICE FOR VSYIICIXRONOUS MOTORS 2 Sheets-Sheet 2 @www ' tors of the feature has,

30 the starting cycle after an initial starting switchx has been Patented No'v. 25, 193O UNITED STATES Miaii'l-,ofi-rica WALTER S. vjPFlfllEEBl., OF SHOREWOOD, WISCONSIN, ASSIGNOR, BY EESN E ASSIGNMENTS,

^ To entre BELIANCE COMPANY,

:immens STARTING DEVICE FOR SYN-'CHRONOIUS MOTORS Application led December 14, 1923. Serial No. 680,642.

This invention relates to new and useful' j, improvements in starting devices for synchronous motors.

Synchronous motors have been generally i 5 endorsed by experts and recommended by the public utilities due to the ,greater amount ofpower whichis obtained in 'ratio to the A`current consumed when compared to the mosquirrel cage type. `This desirable however, been oiset in the past by the diiliculties experienced in the starting of the motor. In the past this has been 'accomplished by an operator manually closing the various circuits at intervals, often resulting in improper Startingand necessitating repeating of the starting` operation,- las it is essential that each step 1n the' starting cycle be made in' its-'proper sequence with the proper/time interval between it and the preceding Step. VAs a result of the obstacles and "ditiiculties experienced in the manual starting of sync cnous motors, they have not been generally adopted, and have been viewed with considerable disfavor.

With the above and 'other objections in mind, this invention has for one of its objects to provide a starting-.device for synchronous `motors wherein the human element isabsolutely eliminated and all the operationsof performed automaticall closed.

. Another o bect of this invention resides,l

in the provision of a starting device for syn-f chronous motors wherein a. prolonged excessive overload or the'failure of any of the steps in the cycle renders the entire device inoperative. A

While in the starting of a' synchronous motor only alternating current is used u` to the time the motor is brought to speed, it is advisable to have both the alternating and direct currents at the board when the initial step of the starting cycle is performed to eliminate the possibility of bringingr the motor upto speed and not being able to complete the cycle due to the direct current not being on the board when it is to be connected with the rotor.

It is, therefore, another object of this 1n- I A further object tion resides 'in the sponsive ,to the motor during the periodvwhen the same is in the 0F WILMINGTON, DELAWARE, A CORPORATION OF aElssul-:n-

vention to provide a starting device of the character: described wherein it is impossible to start the starting cycle unless both alternating and direct current areat, the board.

' Anoth'er'objectof this invention resides in the provision -of means operable upon the failure of any one step in the starting cycle to be'completed in its sequence, and within a predetermined time interval, whereby the entire start' goperation is rendered inoperative.

.of this invention resides in the provisionlof means for producing a time lagbetwee the actuating of the. governing relay and the closing of the direct current'ma-in switch for connecting the direct current with the rotor after the motor has been brought to speed whereby the govern- Y set at a sufciently high value to at all times insure the direct current going on. c

And a. s till` further object of this invenprovision of a compound having a coil of a constant of a variable value and recurrent consumed by the governing relay value anda coil brought to speed.

With the above and other objects in view I y which will appear as the description proceeds,

my invention resides in-the novel construction, combination and ,arrangement of parts substantially as hereinafter described and more particularly defined by the appended i claims, it being understood that such changes precise embodiment of the herein disclosed invention may be made as come within the scope of the claims.

In the accompanying drawings, I have p 'Y illustrated one complete. example of the physical embodiment of my invention constructed according to the best mode I have so far dee vised for the practical application of the principles thereof, and in which:

igure 1 is a view in front elevation of the panel or front switch board of a synchronous motor starting device embodying my.

invention;

Figure 2 is a front elevation of a compound. governing relay employed in connection with my improved synchronous motor starting device;

Figure 3 is a side view thereof; Figure 4 is a diagrammatic showing of the l circuits employed.

Referring now more particularly to the drawings in which like numerals designate like parts numeral 5 designates the rotor and 6 the stator of a three phase synchronous motor which is diagrammatically illustrated in Figure 4.

Heretofore the starting of a synchronous motor has been chiefly accomplished by the manipulation of various switches, the intervals betweei the manipulations of which have been controlled by the operator, brin ing into play the humanelement which is o 'ectionable in that theintervals between the closing of thelvarious circuits are varied.

This invention contemplate'sfthe elimination of the human element as a factor in the starting operation of a synchronous motor, by providing a single starting switch or button S, which closes an-initial circuit to be later described, resulting infthe actuation in proper sequence and at the desired intervals of a plurality of actuating devices insuringr the proper protection against overload and failure of any of the devices to operate at the proper time up to the point Where the motor .is in full operation with the alternating curiront board or panell an'alternating current protective,vtiming relay 18 and two overload relays 19 andV 20; The -rear panel has mounted thereon a direct current magnetic switch 21 which controls auxiliary switches 22 and 23, a resistance .cutout switch 24, a resistance 25, an alternating current, main line switch 26' controlling an auxiliary switch 27 a step-down voltage transformer 28 land current transformers 29 and 30.

The magnetic switch 13 is of conventional design embodying a magnetic coili31, a pivoting armature 32 adapted to, upon attraction toward the coil .byits energization, Aengages amovable contact carried by the armature with a ixed contact 33. The magnetic switch 14 is also of conventional construction including a magnetic coil 34 and a movable armature 35 adapted to be attracted thereto upon .energization andl carrying a pairof throughout the several views, the.

`flanges 57 tures to vary as illustrated, employs a- Vture 66 adapted carrying a pair of movable contacts 67 and 68 movable contact? 36 and 37 which are engageable with ixed contacts 38 and 39, respectively. Themagnetic switch 16 is similar inconstruction to the magnetic switch14 andcomprises a magnetic coilV 40, la movable armature 41 ,controll'in Va pair of movable contacts 42 and 43 which are engageable with .a ypair of iixed contacts 44 and 45, respectively.

rIhe compound governing relay switch 15 is of special construction and' includes `two substantially l J-shaped, longitudinallynaligned core or pole opposite ends 48 and 49 of which are wound -magnetic coils 5 0 and 51, respectively.V Positioned medially of the cores or pole members 46 and 47 is a pivot standard 52 tovwhieh the armatures 53'and 54- for the coils` '50 and 51 respectively, are pivot 55.'y v v The armatures 53 and 54 are rigidly connected at an angle with respect to each other by a bolt or other fastening member 56 which passes through lateral projections or ting bolt or screw 58 cooperatingwiththe fastening member 56 and.permitting a ine adjustment ofA theY angle betweenthe armathe sensitiveness of' the. magwill be laterdescribed. `Thel netic switch', as

54 vtoward its movement of thel armature magnetic coil may 59 passing through' the end thereof and adapted to butt the core 49, as will be readily apparent. `The outer endv of theV arma-- ture 53 carries a movable contact 60" which' adapted to engage a the armatures are lin trated inFigure's2 and'3. A

The relay 17, 18, v19 and .20 are ot the' construction Aillustrated in Letters Patent pivotally secured A by a members 46 and 47 around -the carried by the armatures, a setoo Y be adjusted by a Yset screw ius No.!'1,449,025 'granted `Gustav vO. Wilnis,

Marchf20, 1923 and each includes a relay coil 62, a movable contact bridge contacts 64, the movable contact-being controlled by an armature 65^fwith one end of which suitable .dashr potimeaiis, not shown, 'are` connected. Each of the relays 17, 18", 19 and 20` are identical-in structure with the exception of relay `17 the contacts 64 of which are 'normally open' and only,V close vupon ,operation of the relay.

` TheV direct current magneticV switch,` 21 embodies a magnetic coil 66', and an armato be; ttracted thereto and 63 adapted to l adapted to engage stationary contacts'69 and 70, respectively, when the,armature 66 is attracted to the coil 66 by it'senerLLzation. The auxiliary :switch 22 is controlled from the movable armatureto disengage movable contact 71 from the stationary contact' 72 when said direct. current magneticswitch is lclosed and to close said auxiliary-switch contacts when the direct current magnetic switch is opened. The aum'liary switch`23 switch armature 66, and

is similar in construction to the auxiliary switch 22 and embodies a movable contact 73, which is.eontrolledfrom the magnetic a fixed contact 74. As theoperation of this auxiliary switch is identical with that of the auxiliary switch 22,` further description thereof is deemed unnecessary. The resistance cut-out switch 24 is of simple design, comfprising a movable contact 75 which is in e ect the continuation of the movable contact 67 and which is engaged with a fixed contact 76 when the direct current magnetic switch-21 is opened and is disconnected therefrolnwhen the mag- 'netic switch 21 is closed.

The alternating current main line switch 26 includes a magnetic coil 77 and an armature 78 which controls three movable contacts 79, 80 and 81 adaptedto be engaged with fixed contacts 82, 83 and 84 when the armature 78 Ais attracted to the'coil 77 by its ener zation and to be disengaged therefrom w en the armature 78 is deenergi'zed. The auxiliary switch 27 is controlled directly from the armature 78 and includes a )novable contact 85 which is, actuated by the f armature 78'tobridge a pair of "fixed contacts 86 when the amature 78 is attracted toits coil 77. l

The alternating current is led to the fixed contacts-82, 83. and 84 by three service lines 87, 88 and 89, respectively and the alternating current is connectible with the fields ofthe stator upon closing of the alternating current main line switch 26, through the 92 leading from the The dlrectcurrent is led to the fixedcontacts 93 and 94of the switch 12 on the main switch board or panel by the service lines 95 and 96, respectively, and the movable contacts 97 and 98 ofthe switch 12 are connected with the .fixed contacts 69`and 70 of the direct current magnetic switch, 21 by conductors 99 and 100, respectively, .the

rheostat 10 and thedirect current ammeter 8 being connected in on the as elearly depicted in Figure 4. The direct current is thence connectible with the rotor of the motor when the'direct current magnetic switch 21 is closed, throu h the conductors 101, 102 leading from t e movable contacts 67 and 68, respectively, to the rotor.

The voltage in the embodiment illustrated,

at the A. C. service line is extremely high and for this reason it is desirable tostep down the voltage of the current used at the switch board for controlling the various magnetic switches. To this end the transformer l 28 is provided and one end-of its primary coil 103. connected with line 89 by a conductor 104 and the other end thereof connected with line 88 by a conductor 105,-suitable fuses 106 being provided within the conductors 104 and 105 to provide a factor of safety. 'llhe conductor 12 conductor 100, l

type and the starting switch secondary coil 107 of the transformer 28 has one end thereof connected with one end of a fuse 108 mounted on the front switchboard by a conductor 109 and has its other end connccted with one end of a fuse 110 Ymounted on 'the front switch board by a conductor 111, thus bringing the alternating current of low voltage for operation of the alternating current actuating'magnetic switches to the front switch board.

With the circuits as illustrated in the drawings, the alternating current isbrought to the fuses 108 and 110, devicesV are inoperative.

thrown in, engaging the movable contacts 97 and 98 with the contacts 93 and 94 illuminating the indicating light'll which is connected acrossthe contacts 97 and 98 by conductors 112 and 113, ,the direct current being advanced magnetic switch 2 1, and the coil 31 of the switch device 13 4heilig energized by reason of one end thereof being Yconnected with the Contact 97 by a conductor 114 connected with the conductor 112 and a conductor 115 which 1s connected with a conductor 116, connected to the contact 98, engaging the contacts 32 33 so that upon the manipulation of the and and all of the controlling' Switch 12 is first,

tothe contacts 69 and70 of the starting button S to engage the movable conl the coil 34, conductor 126, contacts 64 and 63 of the protecting relay18 and the overload relays 19 and 20, one Vcontact tective timing relay 18 being connected with one contact 64 of the overload relay 19 by a 7, one contact 64 ofthe overload relay 19 being connected with one contact 64 ofthe overload relay 20and thence to the fuse 11G-through a conductor 129 connected with the other contact 64 of the overload relay 2 'The stop switch is of the normally closed of the normally 64 of the proopen tyge and a release of the pressure on the button permits its movement to open posi'- tion as a result of which the circuit of thecoil 34 is then through the conductor 120, con- .tact 119 of the startswitch, conductor 130 which is connected with the movable contact 37 of the switch device 14, conductor 131` which leads from the `movable contact 37 to the movable contact 36, contacts 36 and 38,

conductor 132connccting the contact 38 with switch and the remaining of the circuit previously described. Y

the contact'118 and thus through the stop v As stated, immediately upon Vthe energization of the coil 34, contacts 36 and 38, and'37 and 39 are made, as a result of which the magnet 77 of themain line alternating current `-switch 26 is energized, the 'circuit thereof being closed through'a conductor 133 leading from thefuse' 110, to one end of the coil 77, through thecoil, a conductor 134 connecting the other end of the coilwith Vone Contact "o 860i the auxiliary switch 27 through aconf ductor V135 leadingl "from the contact 86, through a conductor 136- leading from the conductor 135vto the contact 39, contact 37, thence to the fu se`108 through'the conductor 130, contact vv119 and conductor 120,- closing the switch 26 to engage its contacts 79 and 82, 'L80 and 83 and-81 and 8 4, and'connecting the stator 6 of the motor with the A; C. line, the circuits being through conductor 87,con'tacts 2'0' 82 and 7 9 and conductor 90.to the stator.con

" ductor 8 8,'contacts 83 and 80 and through conductor 91 to the stator, conductor 89, contacts 84 and 81 and to the stator, through conductor92, as a result of which the motor `j isstarted. The magnetic switch device 16 is 'Z actuated simultaneously with the main line switch device 26, if not sightly prior thereto `due vto its being of a lighter .type and having A less inertia to overcomethe circuit of Ythe coil 40"ther eof being through conductor 120,

'contact 119, conductor 130, contacts 37 and' 39, conductor 136, conductor 135, throughthe coil 40, conductor 1 37, cnductor138f, through contacts 7 2' and 71 of the auxiliary switch 22,

.35 conductor 139 and thence tofthe fuse 110 throughA the conductor 133, closing the con' tacts 42 and 44, 43 and 45. As 'the contacts 86 are bridged by the movable contact 85, the circuit ofthe protective 40 `timingrelay 18 is closed-'through conductor 120, Contact 119, conductor 130,- contacts 37 and 39, conductor 136, conductor A135,the .auxiliary switch 27, conductor 140, through Y the coil 62 of the relay 18,"through conductor A 45. 138, auxiliary switch 22, of the .directcurrent magnetic switch, conductor 139, thencei to the fuse 110 through conductor133. The current transformers 29gand l30 are connected byacommon conductor 141 .with the ground G and to a conductor' 1427which leads to one v end of the coil 51 ofthe governing relay device 15, the other end of the-coil being con` nected with the movable contact. 42 of the` control device 16 by a conductor 143, the con- Y' 55, tacts 42 and 43 being connected by acommon conductor 144 and with one side of an alternating ammeter 9 Vby a'conductor 145, vthe other 'side otle ammeter being connected by a conductor .146 with the -coils 62 of .the

#30 overload relays 19 and 20, the ther side of the overload relay 19 being connected] with the stationary contact 44 of the device 16 by a conductor 147 sind the other.`side of the coil 62 of the overload Yrelay -20 being connected f with the stationary contact 45 byaconduetor conductor 158 by a conductor 160 and the (3 magnetic switch 16 is energized.

The coil 51 of the device 15 is thus energized and the value of the current flowing therethrough -is in proportion tothe value ofthe current taken by the starting action of the motor which is very high at the initial start` and decreases as the motor speed increases. The coil 50 "of the device 15 is also energized, its circuit being from the fuse so through the conductor- 151, through thel coil 50, through conductorJ 152, through c'onduc tor 140, through the auxiliary switch 27, conductor 135',4 conductor 136, contacts 39 and 37, conductor 130,`contact 119 and to the fuse a5 108, through conductor 120. The value of the current supplied thecoil 50 is constant andas the strength of the coil 51 is extremely high during the starting of the motor as V'previously described, the armature 54 will 90' the coil 62 ofrelay 17 andbac'k' to the otherfl side of theline through a conductor 154 con-l nected with'the switch contact 97. 'i YAlfter the interval ofseveral seconds, vaccording to the adjustment of the timing relay 17. contact 63 is engaged with the contacts 105 64 bridging the same, as a result of which coil 66 of the direct current magnetic switch? -21 is energized, closing the direct current to the rotor through the contacts 69l and 67 conductor 101 and""through the contacts 70 .1.1.9

and 68 and con'ductor'102, at the Sametime' opening the contacts 7 5` and 76' ofthe aux# 'iliary' switch 24. opening the resistance I25 V`which has been in the rotor line to"preveft the building in the rotor of a high voltage 115 and also 'breaking the contacts 71 and 72 of' theqifuxlharyswitch 22 and contacts 73 and 74'0 4the auxiliary switch 23. v l' The circuit ot the coil 66 vhen energized is through the switch contact 97,' conductorg120 154',v conductor 155, contacts 63 and,64,` conductor 156, through the coil 66 through the conductorf157, through the auxiliary 'switch \23,^conducto'r I158 to the other con,tact98 l throughfthe conductor 116. Thero eng of the 'auxlhary switch 23 does notl reak thev 7 continuity ofthe circuit of the coil 66 but merely throwyslnto'the circuit a,A resistance 159, one end 'of wluch is connected with the other end of which is connected with the con-' type of control does not give protection durductor 157 by a conductor 161. ing the-starting period, which is the period of The opening of the auxiliary switch 22 high current, by current relays, but the conbreaks the continuity of the magnetic coil 40 trol allows certain time for the motor 'to -come as a result of which the overload relays 19 to.speed and ifthis is not accomplished the and 20 are .thrown into the line as well as control is brought to the oif position..y the alternating jcurrent ammeter 9 and the The starting device illustrated alsopromotor is then running at fullspeed under norvides a means through a timing relay 1,7 mal conditions. The openingof the auxiliary whereby a lag is introduced between the oper- 10 switch 22 also cuts out the protective timing ation of governing relay 15 and vmagnetic 75' relay 18, one side of whichis connected with switch 21. This time lag has the va ue in conductor 138, as previously described. that it allows a setting on the governing relay While therdrawingsand the above descrlpwhich assures its o eration providing Y tion refer to an arrangement wherein the dithe motor comes to speed, y giving the motor 15. rect current is obtained from an external additional time to come near Vsynchronous source, it -will be apparent that this invenspeediafter the governing relay has operated,- tion may be employed without any change, and in .a self excited motor gives the D-C with asynchronous motor of the self-'excited generator additional time in which to build type, i. e. one having means such as a con-A up its voltage.

ventional exciter, not shown, for generating What I claim as m' invention is: 85 and delivering its own direct current to the 1. An appliance ofy he character described, v lleads ,95 `and 96. In this structure therelay comprising Va synchronous electric motiva switch '13 is eliminated and the relay 34 then machine having a direct current supply cirdirectly'connected with the contact 12B/of cuit for the field, a plurality of automatic the stop switch. 'It is a well known fact that devices adaptedto be operated by the direct the voltage of the direct current generated in current, e a plurality of automatic devices synchronous motors of the self-excited type adapted to be operated by alternating curis not built up simultaneously with the comrent, a plurality of electrical circuits including to speed of the motor and for this reason ing the automatic devices and adapted to. be

a time lag must be provided between the time closed .in sequence at predetermined interthe motor comes to speed and the time the vals to eifect the starting of the machine, a direct current is connectedwith the rotor 5. starting switch adapted to be actuated to- This time lag is provided bythe timing relay close one vof the circuits to eiect the auto-n 17. matic lactuation in Sequence of said devices,

By reason of the anglebetween the armaand means operable upon the failure of any wo tures 53 and .54 of the governing relay 15 beof said 'automatic devices to actuate within ing adjustable, -the responsel of 'this relay to a predetermined period of time to render inthe condition in the alternating current line operative all of said devices in operative pois readily adjustable and the period at which sition. Y Y

40 the contacts 60 and 61 close controlled. 2. The combination with a synchronous 1 The rheostat 10 may be eliminated, if deelectro-motive machine adapted to be started sired, as the same is only incorporated in by having alternatingv current applied to the the direct current line when specified by the stator thereof and to have direct current apcustomer. ,la plied to the rotor after the motor has come From th'foregoing description taken in to speed, ofagoverning relay controlled from 110 connection with the accompanying drawings, the alternating Acurrent supplied the stator it will be readily obvious that upon the failat a voltage derived from the stator circuit, ure of any one of the devices in the starting a timing relay, a circuit includingY said timcycle of the motor the entire starting operaing relay 'and said governing relay, said tuen will be thrown out in a predetermined governing relay bein' actuated upon the ma- 115 time and it will be necessary to again start chine coming to spec to throwin the circuitc. at the beginning. Further-,that it is imposof said timing relay, and means 'actuated by sible to'complete the'initial step in the cycle said timing relay within a predetermined Without having bothalternating and direct period oftime after the actuation of said current at the board. s governing relay to connect the direct cur-` 129 With this scheme of control is provided a rent with the rotor, said timing relay providmeans whereby theoverload relays are ining ay time lag between the time when the serted into the circuit only after thefstart has machine comes to speed and the direct curbe'en completed which ,permits af closer setrent is connected with therotor thereof.

` ting on the seme giving better: protection to 3.' The combination with a synchronous 125 the motor. Atv the same time a protective motor adapted to be started byhaving altertiming relay is`built into the Icontrol which nating current applied to the stator thereof will disconnect the motor from the line in and rto have direct current applied tov the case the'start has notbeen completed in a prerotor ofthe motor after the motor has come determined interval. As is understood, this to speed, of agoverning relay controlled from 13o swltch, an overload relay within the circuit by said timmg relay within a'predetermined period of time after the actuation of said governing relay to connect direct current with the rotdr, sai-d timing'rel'ay providing a time lag between the time when the motor comes'to speed and the direq: current is con-A nected with the rotor th eef, 'and means operable to disconnect'thwalternating cur-J `rent from the stator of the ,motor upon the lfailure of direct current to-be supplied the rotor` within a predetermined period of time.

4, rlhe combination withv a synchronous motor adapted to be startedby having alterhating current applied to thestator thereof and to have direct current applied to the rotor of the motor after the motor has come arcanos speed within a predetermined period of time. 6. The combination with a synchronous motor adapted to be started by having alternating current-applied to the stator thereof and to have direct current applied tothe rotor of the motor after the motor has come v to speed, of. a main line alternating current magnetic switch adapted to Aconnect the stator, ofthe motor with a source of alternat, ing current, a circuit including said main line magnetic switch, a vmagnetic relay switch adapted to, -upon actuation, close 'said firstmentioned clrcuit -to actua-te 'the mainline switch, an overload relay within the circuit of said magnetic relay switch ^and operableA upon the occurrence of an overload to break the continuity of the circuit thereof and dis'-v connect the motor stator'from its source of alternating current, means operable during` the period the motor is being brought Yto speed to render said overload relay inoperatO Speed, Ofa main line altrlating Current tive, a protective timing relay adapted tobe magnetic switch adapted to connect the stator of the motor with a source of alternating current, a circuit includingsai main line magnetic switch, a magnetic relay switch 'adapted to,- upon actuation, close said rst mentioned' circuit and actuate the main line switch, an overload relay within the circuit 'of said magnetic relay, switch and operableA uponthe occurrence of an overload to 'break the continuity of the circuitthereof and disconnect the motor stator -from its source of alternating current, and means operable during -the ,entire period the Vmotor'is being broughtto speed to render said overload `re lay Yinoperative.v d

v5. rEhe combination with a synchronous ,motor adaptedto be started by having alternating current applied to the stator thereof and to have direct current applied to the rotor of the motor after the motor has come to speed, of a main line alternating current f magnetic switch adapted to connect the staiV tor 'of the motor with a source of alternating current, a circuit including .said main line magnetic switch, a magnetic relay switch lay. device is 'broken and, thestator discon-v adapted to,upon actuat1on,fclose said rst mentioned circuit to actuate-the main line the continuityof the circuit thereof andA disconnect the motor lstator from its source Y- `of alternatin current, means operable during the perio the motor is being brought to;

'speed to render said overload relay inoperative, and a protective timing' relay adapted to be thrown into thecircuitrof saidV magnetic relay device during the period said overload relayv is rendered inoperative whereby the continuity of theecircuit of said magnetic rerv nected from its source of a1 rnating current thrown into the circuit of said magnetic relay device during theperiod said overload re# lay is rendered inoperative whereby the continuity ofthe circuit of said magnetic relay device is broken and the stator disconnected from its sourceof alternating current upon upon' the failure of the motor to come to to. l

for closing said direct current magnetic! 'lAutomatic starting means for synchronous motors, comprising; a normally open excitation circuit including a supply source a normally open controlling circuit therefor and in parallel therewith; a ndrmally open circuit in parallel with saidrexcitation circuit and with saidontrolli'ng circuit, and in cluding means. for closingsaid excitation circuit; means in said controlling circuit for closing said last named circuit; a manually closed vmotor actuating circuit; and means iniuencedby the current in said motoriactuating circuit for closing said controlling cirlcuit and thereby bringingabout the closing' of said excitation circuit. J

i 8. Automatic startingmeans for synchronous motors, comprising; a normally open excitation'circuit including a supply source; a nor ally open` controlling circuittherefor" and in parallel therewith; a, normally open intermediate circuit'in `parallel with said excitation, circuit and said controlling circuit,F

and including meansfor closing said excita-l tion circuit; means included in. said controlling circuit for closing said intermediate cir,-

A/cuit; a manually closedmotor actuating circuit; means influenced by the current in said motor actuating circuit'for closing 4said con; trolling' circuit; and a normally closed circuit parallel with said excitation circuit for rendering saidmanually closed actuating circuit operable.

9. Automatic starting means for synchro` nous motors, comprising; an excitation circuit open at a plurality of points and including n supply source; a normally open controlling` circuit therefor 'and in paiallel therewith; a normally open intermediate circuit in parallel with said excitation circuit and said' Acontrolling circuit, and including'.

means for closing said excitation circuit; meansin said controlling circuit for closing said intermediate circuit; a motor actuating circuit; manually operable means for efecting the closing of saidactuating circuit;

means influenced from said motor actuatingsaid controlling circuit;

circuit for closing one of the open points of said excitation circuit being manually closable; a shunt circuit including said-supply source and closable by the closing of said manually vclosable point 1n the excitation circuit, and including meansA for rendering th operation of said manually .A closable means for the motor actuating cirthe. closing thereof;

cuit effective only when the shunt circuit is closed. Y

' 10. In an automatic starting system for synchronous motor a motor actuating circuit; manually operable means for effecting an excitation circuit; a shunt circuit in connection therewith; and means in said shunt circuit for rendering said manually operable means effective only when said shunt circuit is closed.

1l. In a starting system for synchronous motors; an excitation circuit including a supply source; a controlling circuit therefor and in 'parallel therewith; a motor actuating circuit; means iniiuenced from said motor actuating circuit aiid biased thereby to close said controlling circuit; and means responsive to current consumed by the motor actuating circuit for counteracting the bias of said first named means until the motor approaches synchronous speed.

12. In a starting system for synchronous motors; an excitation circuit manually closable to include a supply source; a controlling circuit therefor and in parallel therewith: a transformer; a motor actuating circuit including the primary of said transformer; a

i governing circuit including both a secondary counteract the bias of .til the motor comes a motor actuating circuit including a motor;

means influenced by said motor-actuating circuit and biased thereby to close said controlling circuit; means responsive to current passing through the motor in said motor actuatin circuit for counteracting the bias of said. rst nanred .means until the motor reaches synchronous speed; and a timing relay in said controlling circuit for closing said excitation circuit.

14. In a starting system for'lsynchronou's motors; an excitation circuit including a supply source; a controlling circuit for said excitation circuit and in parallel therewith; a motor actuating circuit; means inductively controlled by a circuit in parallel with said motor actuating circuit and biased to close said controlling circuit; and means inductively responsive to current consumed by the motor actuating l circuit, and operative to said biased means unup to synchronous speed.

l5. Automatic starting means for synchronous motors, comprising; an excitation circuit including a supply source and a plural`- ity of switches; a circuit for controlling said excitation circuit, in parallel therewith and including a switch; an intermediate circuit in parallel *ith both said excitation circuit and said controlling circuit, and including switch operating means for a switch -of said excitation circuit; said intermediate circuit also including a switch o erated by timing rela-y means in said contro ling circuit; a Inotor actuating circuit; a plurality of circuits inductively connected with said motor actuating circuit, one of said inductively connected circuits including means 'biased toy close the controlling circuit for said excitation circuit, and'also including means for closing an operating circuit through a motor; another of said inductively connected circuits including means for counteracting the bias of said biased means until the motor comes up to synchronous speed; and a shunt circuit connected Witlisaid excitation circuit -and including means for rendering the operation of all of said circuits and means ineffective until said shunt circuitis closed.

16. In an automatic starting system for synchronous motors; a motor actuating circuit including a switch; a circuit inductively connected with said -motor circuit and including means for operating said switch; an

cludingmeans for efecting the closing of A said excitation circuit when the motor comes up to synchronous speed; a controlling circuit in parallel connection with both of said inductive circuits; and a protective circuit in parallel connection with all 'of said inductive circuits and including timerelay means for opening said controlli-ng circuit after a predetermined time interval; and means operated by the Y for connecting the field of the motor to a diy 5 d wlndmg to 'eli'ect the connection of saidield' said motor, a bypass trolling the connection tor, said relay` connecting closing of said excitation circuit to open said protective circuit.

17. In a starting system for synchronous motors including alternating and direct current sources,- an electro-magnetic motor actuating, switch in the alternating current source, a manually `operated circuit closer thereforf,.and direct current means in the motor ieldsupply line operable to control the operative eiectiveness of said circuit closer. f L

18.111 a starting system for synchronous motors, electro-responsive switch, mechanism rect current supply circuitv for running, an means for controlling said switch mechanism including a relay operated responsively to the variation of starting current in the mothe direct current supply circuit to -the motor field when the acceleration of the motor decreases to synchronous speed. Y

-Q' 19. The combination with a synchronous Imotor, of a main line switch for controllmg /said motor, an overload relay for opening said switch,l when excessive current flows to shunt for said overload rela a switch for controlling the ield circuit ol said motor, a relay for closing said last-named switch'when said motor attains a predetermined speed, and means for opening the circuitfotlsaid bypass shunt simultav n eously with the closingof said field circuit 2O.` The combination with a synchronous motor, ot anexciter for supplying current to the field ot said motor, a switch for conbetween said exciter and iield, an overload relay for protecting said motor against excessive currents, a bypass shunt for said overload relay, and means connected with said field circuit switch for opening said bypass shunt simultaneously with the `closingof `said icld circuit switch.

l21K. The combination with a synchronous motor, of a mainline switch y'for controlling the current to said motor, an `overload relay for controlling said main line-switch, a cur- Y rent transformer connected with^the supply v overload relay,

load relay, and

circuit. for said motor for operating said a bypass shunt for said"over means for opening said bypass shunt to permit; operation of said overa load relay independently of said bypass shunt during full speed operation of said motorL v 22. The combination with asynchronous motor, of an armature supply line, means for connecting the motor armature and supply line, electro-responsive means arrangedfor controlling vthe operation oisaid `automatic connecting means, an actuating cirsaid cuit for said eleCtro-responsive means,

' nous s automatic n 'I `motor 1s 1n a condition less than at normal accelerating speed.

23. In combination, an alternating current motor having a eld ,winding arranged lto be Sul?- connected to a direct current sourcel of ply for `synchronous running of the' motor,

speed and a` time interval device connected' motor and to run as a 7synchrowinding to said direct current source, the said device being provided with by the motor for regulating the timing there-l of to effect said connection when the motor accelerate normally to substantially synchro- 24. n a starting system for synchronous -motors, an electro-magnetic motor actuating switch, a v `manually operated circuit closer therefor, said switch a d circuit closer being arranged in a circuit derived from the motor larmature supply line, and means in the motor ield supply line for rendering said circuit closer operatively effective only upon a predetermined condition ofthe motor field sup'-Y ply line. y

In'testimony whereof I aiX my signature.

WALTER S. PFEIFER.

actuating circuit being capable ot completion J to normal operating condition only when the means controlled 

